Supporting multi-resolution out-of-core rendering of massive LiDAR point clouds through non-redundant data structures

ABSTRACT

In recent years, the evolution and improvement of LiDAR (Light Detection and Ranging) hardware has increased the quality and quantity of the gathered data, making the storage, processing and management thereof particularly challenging. In this work we present a novel, multi-resolution, out-of-core technique, used for web-based visualization and implemented through a non-redundant, data point organization method, which we call Hierarchically Layered Tiles (HLT), and a tree-like structure called Tile Grid Partitioning Tree (TGPT). The design of these elements is mainly focused on attaining very low levels of memory consumption, disk storage usage and network traffic on both, client and server-side, while delivering high-performance interactive visualization of massive LiDAR point clouds (up to 28 billion points) on multiplatform environments (mobile devices or desktop computers). HLT and TGPT were incorporated and tested in ViLMA (Visualization for LiDAR data using a Multi-resolution Approach), our own web-based visualization software specially designed to work with massive LiDAR point clouds.

KEYWORDS:

• LiDAR
• web-visualization
• efficient data structures
• multi-resolution
• out-of-core

Acknowledgement

The LiDAR datasets used in this article belong to:

• LiDAR-PNOA¹⁰ data repository. Provided by Instituto Geográfico Nacional de España.

• PG&E Diablo Canyon Power Plant (DCPP): San Simeon, CA Central Coast¹¹ and Sunset Crater Volcano National Monument, AZ.¹² This material is based on LiDAR Point Cloud Data Distribution and Processing services provided by the OpenTopography Facility with support from the National Science Foundation under NSF Award Numbers 1226353 & 1225810.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Dielmo3D website: http://www.dielmo.com/en/.

2. Potree website: http://potree.org/.

3. MegaTree website: http://wiki.ros.org/megatree.

4. Apache server website: https://httpd.apache.org/.

5. LAS file format standard definition: https://www.asprs.org/.

6. GZIP website: https://www.gnu.org/software/gzip/.

7. Potree website: http://potree.org/.

8. OpenTopography website: http://www.opentopography.org/.

9. LiDAR Online website: http://lidar-online.com/tools/maps.

10. LiDAR PNOA web site: http://pnoa.ign.es/presentacion.

11. OpenTopography web page of the San Simeon dataset: DOI: http://dx.doi.org/10.5069/G9CN71V5.

12. OpenTopography web page of the Volcano dataset: DOI: http://dx.doi.org/10.5069/G9K0726C.

13. GZIP website: https://www.gnu.org/software/gzip/.

Additional information

Funding

This research was supported by Xunta de Galicia under the Consolidation Programme of Competitive Reference Groups, co-founded by ERDF funds from the EU [Ref. ED431C 2017/04]; Consolidation Programme of Competitive Research Units, co-founded by ERDF funds from the EU [Ref. R2016/037]; Xunta de Galicia (Centro Singular de Investigación de Galicia accreditation 2016/2019) and the European Union (European Regional Development Fund, ERDF) under Grant [Ref. ED431G/01]; and the Ministry of Economy and Competitiveness of Spain and ERDF funds from the EU [TIN2016-75845-P].

Notes on contributors

David Deibe

David Deibe received the BS degree in computing science from the University of A Coruña in 2014. He is currently a PhD student in the Department of Computer Engineering at the University of A Coruña. His research interest include LiDAR data, efficient data structures, high performance rendering, distributed storage and computing  and big data.

Margarita Amor

Margarita Amor received the BSc and PhD degrees in physics from the University of Santiago de Compostela, Spain, in 1993 and 1997, respectively. She is currently an associate professor in the Department of Electronic and Systems, University of A Coruña. Her research interests include the areas of computer graphics and parallel computing.

Ramón Doallo

Ramón Doallo received a B.S. in Physics in 1987 and a Ph.D. in Physics in 1992, both at the University of Santiago de Compostela. He has been teaching at the Faculty of Informatics of the University of A Coruña (UDC) since 1990 and was promoted to the position of Full Professor in 1999.  From 1994 till 2017 he led the Computer Architecture Group at UDC. His main research area is High Performance Computing (HPC). He has 30 years of research experience in research topics of computer architecture, supercomputing, parallel and distributed computing, cloud computing, Big Data processing, and geographic information systems. He has published in these fields more than 200 papers in international journals and conferences.